1. Field of the Invention
The present invention pertains generally to the field of electronic musical instruments and is more particularly directed to a novel sound pick-up for string instruments and associated electronic circuits for encoding the pick-up output in M.I.D.I. compatible serial digital format for driving a sound synthesizer or other sound processing system equipped with a standard M.I.D.I. interface.
2. State of the Prior Art
Sound or music synthesizers have come into widespread use and are available from a growing number of manufacturers. While the various models currently offered differ in terms of capability, flexibility and complexity, many are equipped with a M.I.D.I. (Musical Instrument Digital Interface) interface, a unified data communication standard for electronic musical intruments which enables systems of different manufacture to be used together. For example two or more synthesizers of different make may be simultaneously controlled or played from a single keyboard.
At present, the keyboard remains the most commonly used input device to MIDI sound synthesizers. However, many performers and musicians are more proficient with or have a preference for non-keyboard musical instruments, particularly among the great numbers of guitar players. A need therefore exists for MIDI interfaceable string instruments and more precisely, for sound pick-up systems for musical string instruments having a MIDI compatible output.
U.S. Pat. No. 4,606,255 issued Aug. 19, 1986 to Hayashi et al. and other patents cited therein, particularly U.S. Pat. No. 4,357,852 issued Nov. 9, 1982 to Suenaga, are directed to guitars for use with a sound synthesizer. These guitars derive an input signal to the synthesizer by detecting the fundamental frequency of a vibrating guitar string. This requires that the guitar pick-up be connected to circuits capable of accurately discriminating between the fundamental and the multiple harmonic frequencies simultaneously generated when any of the guitar strings is played. In practice however, it happens under certain circumstances that the system erroneously identifies a harmonic frequency as the fundamental, and thus causes the sound synthesizer to generate an output note other than the one actually played by the performer. In addition, the currently available MIDI guitar sound pick-up systems are excessively costly and not widely affordable.
A continuing need therefore exists for more reliable and lower cost MIDI interfaceable pick-up systems for musical string instruments.